It was bound to happen. Lester has been the anchor on a Boston staff that has been hit hard by injuries this season, but after pitching four near perfect innings in Tuesday’s start, he was forced from the game with a strained latissimus dorsi muscle.

The lat is a broad muscle that spans the middle of the back in an area known as the thoracic region. It continues upward before attaching to a groove located on the upper arm bone, the humerus. It is responsible for moving the arm inward toward the midline, extending the arm outward, and internally rotating the arm at the glenohumeral joint. It also works in conjunction with the rotator cuff muscles to slow the arm when it is violently whipped toward the plate during pitch delivery. The muscle gained notoriety recently after White Sox pitcher Jake Peavy needed a rare surgical procedure to repair a detached lat.

Fortunately it sounds like Lester’s injury is located in the lower lat, away from the shoulder and closer to the back. While early indications suggest Lester’s injury is not as serious as Peavy’s, it is still something to be concerned about. Just last year Lester’s teammate, Josh Beckett, missed an extended period with a similar injury. The Red Sox have vowed to put their young ace through an extensive evaluation to determine the extent of the injury, but rest will be key for an injury of this nature. The Red Sox placed Lester on the disabled list Wednesday to give him ample time to recover, so he will become the fifth and final member of the Red Sox’s Opening Day rotation to miss at least one start this season. Alfredo Aceves will be called upon to start Sunday’s first-half finale.

Like Lester, Baker also exited early Tuesday after an elbow strain forced him out after five scoreless innings. Initial testing has determined that the injury is a minor flexor strain, so with the All-Star break coming up, the Twins will skip his next start Sunday to give him extra time to rest.

The worry here concerns Baker’s history of elbow problems. He struggled throughout the second half of last year with soreness in the elbow and ultimately needed offseason surgery - an arthroscopic debridement to remove several bone chips in the area. While the new injury is muscle-related instead of bone-, it still raises a red flag. Baker’s issue could be mechanical, and an improper approach could be placing undue stress through the elbow joint. Look for Minnesota to also take advantage of the built-in break, and don’t be surprised to see Baker hit the disabled list. Anthony Swarzak will get the start Sunday in Baker’s place.

Pujols is living up to his nickname - “The Machine” has returned to action just 15 days after fracturing his left wrist. A CT scan confirmed the crack in his distal radius has formed a successful union, allowing Pujols to return four weeks ahead of schedule.

Fantasy owners are well aware that the three-time MVP should immediately be reinserted back into lineups – he was in St. Louis’ Wednesday - but they should also anticipate an initial drop in power. A quick snap of the lower wrist during the swinging motion provides the bat a jump in velocity; and thus, a faster bat allows the hitter to drive the ball further. Any limitation in Pujols’ bat speed caused by his injured wrist could result in fewer home runs. Pujols has performed well in a batting cage, but he will need time to find his rhythm at the plate. Pujols’ return has pushed Lance Berkman back to the outfield.

Reyes’ quest for the National League MVP award was put on hiatus over the weekend after the speedster suffered a Grade I hamstring strain. Reyes’s left hamstring became tight after he ran to first base, and a subsequent MRI confirmed the injury. He has yet to hit the DL, but Reyes will take his time because he knows the dangers of rushing back from an injury of this kind. In 2009, Reyes prematurely returned from a partial hamstring tendon tear in his right leg. The tear worsened and became a complete tear before involving the muscle belly as well. The injury ultimately limited Reyes to 36 games that year. As we’ve learned recently with Carl Crawford, even a Grade I hamstring strain cannot be taken lightly. The muscle group is needed to accelerate and decelerate the legs during running and is necessary for explosive movements. Reyes’ injury has shown signs of improvement, but returning too early can prove costly.

Expect the Mets to proceed with caution. Whether they elect to trade or attempt to re-sign the 28-year-old, he must be healthy for the team to get max value out of him. A trip to the DL remains a strong possibility, and I wouldn’t be shocked to see Reyes miss or play very sparingly in the All-Star game.

Braun’s strained calf has not garnered the attention Derek Jeter’s did, but his is certainly more significant for fantasy owners given the difference in their numbers this season.

Braun suffered a mild strain of his calf over the weekend and has yet to play since suffering the injury. Braun, another NL MVP candidate, underwent an MRI Wednesday that revealed inflammation in the muscle. It appears Braun could return as early as Friday, but the Brewers may opt to hold him out for the rest of the first half, and the All-Star game as well. Remember, the calf isn’t a lone muscle, but actually a complex made up of two muscles, the gastrocnemius and the soleus. The two muscles work synergistically to plantar flex the foot, a key component in pushing off and essential to a quick first step. A strain to the area can become extremely nagging if not fully healed.

Braun’s owners should be optimistic about a potential weekend return, but don’t be surprised if he remains out until after the break to prevent this situation from becoming worse.